1. Field of the Invention
The present invention relates generally to a cooling system for use with electronic devices, and more particularly, to an air jet impingement cooling method used with a miniature pin-fin heat sink.
2. Description of Related Art
Mechanisms to remove the heat from microelectronic packages are receiving greater attention due to the inherent power density increases associated with higher levels of integration. This is especially true with the microelectronic packages used in supercomputers, for example, those manufactured by Cray Research, Inc., the Assignee of the present invention.
The techniques which the packaging engineer may use to reject these high levels of heat generation often conflict with electrical design parameters and goals. More specifically, the greater speed of these packages may require closer spacing, or the project may set goals to package the system within a given volume, thus reducing the available volume within which the thermal "conduit" may exist.
The techniques employed for cooling microelectronic packages must also be reviewed at each packaging level. For example, a low temperature coolant technique may produce efficient packaging at the chip and board level, and yet require extensive hardware and volume at the higher packaging levels.
Air-cooled electronic systems traditionally exhibit large board-to-board spacing to allow room for heat sinks and also to create a low-resistance fluid path. A number of difficulties are present in this situation:
1) The path of least resistance for the fluid is around the heat sinks. Thus, much of the fluid passes by the IC packages unheated.
2) The fluid often follows a cross flow path across an array of IC packages on a printed circuit board, so that the packages furthest downstream are exposed to a higher temperature fluid due to heat gain from upstream packages.
3) In general, the heat sink size must be proportional to the heat generation of the IC package.